Hi, I'm trying to run bibexport.sh on a LaTeX aux file to produce a
subsetted .bib file. But when I run ./bibexport.sh it gets as far as
creating the new .bib file but doesn't write anything to it. Instead I
get the error:

sed: illegal option -- r
usage: sed script [-Ean] [-i extension] [file ...]
sed [-an] [-i extension] [-e script] ... [-f script_file] ...
[file ...]


Can anyone tell me what I'm doing wrong? I've read the user guide,
searched the web etc, am stumped.

Many thanks in advance,

Nick